The perils of life around the real Mount Doom

New Zealand’s Mount Tongariro erupted today for the second time in four months.

A photo I took a few years ago. Lake Taupo, with Mount Tauhara (another volcano) in the background. Taupo isn’t a placid lake filled with trout. Well, it is. But it’s also the caldera of one of the world’s biggest supervolcanoes. Uh – yay.

The blast happened without warning. Geological and Nuclear Sciences staff had been worried about possible eruption from the next-door volcano, Ruapehu. But nothing from Tongariro.

How it will develop – if it does at all – remains to be seen. The eruption earlier this year lasted for days, dropped ash across my home town of Napier, and sent a cloud of hydrogen sulphide drifting across the North Island. That reached Wellington, where I live now.

Still, it could be worse. It could be nearby Taupo, one of the world’s 50-odd “supervolcanoes”. Taupo last erupted in 186 AD and gave the Romans spectacular sunsets (think about it!). But that blast was a tiddler compared to the real ‘blow’, 27,000 years ago. That mega-eruption sent over 1150 cubic kilometres of debris rocketing skywards, annihilating everything in the central plateau and blowing a great gouge out of the crust.

It’s not too bad – these things happen & while Tongariro’s been quiescent for a while, its neighbour Ruapehu erupts every few years. We’ve got some offshore volcanoes which are particularly active. We get used to it. The bigger issue is the related one – earthquakes.

I find the science around volcano and earthquakes very interesting. It’s always been sort of neat to read about it, and listen to the commentary about how little we actually know. (Specifically with regard to timing eruptions and quakes).

British Columbia is a great earth-quake example, where they know it’s coming, but can’t tell when. The statistical models say a quake over 7.0 is basically guaranteed in the next 30 years – but really that could mean tomorrow. (It’s statistically just as likely to be tomorrow as it is 29 years and a day from now.)

Books (and movies) like The Hobbit might be sci-fi/fantasy, but there are so many real elements in them. I think it’s probably both awe-inspiring and dread-inducing to be so close physically to a ‘Mount Doom’, especially when it’s laying in wait under a seemingly placid lake.

The science is definitely interesting – for abstract as well as practical reasons! Quakes and volcanoes are very much a fact of life here in NZ, yet it’s surprising how the science of it has really only been nailed down in the last generation or so. And it is, indeed, entirely a probability game.

As an aside, I always found some of Tolkien’s geography a bit odd – square-shaped mountain ranges with a volcano sitting isolated nearby, that kind of thing. Of course he had no idea about plate tectonics, and a lot of his world had been shaped by deliberate ‘magical’ action anyway, according to his own mythologies…but still…